Platen printing press



May 25, 1943. w. c. RUPP 2,320,100

v PLATEN PRINTING PRESS Filed Sept. 3, 1941 5 Sheets-Sheet 1 INVENTOR. WILLIAM C.RUPP

ATTORNEYS.

May 25, 1943.

W. C. RUPP PLATEN PRINTING PRESS Filed Sept. 3, 1941 5 Sheets-Sheet 2 1 INVENTOR. WILLIAM C.RUPP I? 1|m\ l8 BY ATTORNEYI May 25,1943. 'w. c. RUPP PLATE PRINTING PRESS Filed Sept. 3, 1941 5 Sheets-Sheet 3 ITS-.4.

ATTORNEYS.

INVENTOR. WILLIAM C.RUPP

May 25, 1943. w. c. RUPP 2,320,100

PLATEN PRINTING PRESS Filed Sept. :5, 19 1- s Sheets-She'et 4 E; El A ATTORNEYS,

May 25, 1943.

W. C. RUPP PLATEN PRINTING PRESS Filed Sept. '5, 1941 5 Sheets-Sheet 5 INVENTOR. WlLLIAM C.RUPP

q Q41 ATTORNEK.

Patented May 25, 1943 1 PLATEN PRINTING PRESS William C. Rupp, Parma, Ohio, assignor to The Chandler & Price Company, Cleveland, Ohio, a corporation of Ohio Application September 3, 1941, Serial No. 409,389

17 Claims.

This invention relates, as indicated, to printing presses and more particularly to platen printing presses of the type provided with pneumatic suction devices for feeding sheets to and delivering them from the platen of the press.

Suction devices of this character usually include oscillatable tubular arms provided with sucker tip assemblies adapted to engage or contact the sheets, and valves for periodically breaking the vacuum in the arms and sucker tips when suction is not desired. To prevent injury to the type form and other parts of the press in case of failure of the feeder sucker tips to feed a-sheet to the platen it is customary in such cases, pending restoration of the vacuum inthe sheet-feeding means, to either stop thepress or move the throw-off lever into operation. Where means is provided for automatically operating the throw-off lever under such circumstances, such means may desirably be of *the,

type disclosed in Johnson Patent No. 2,185,440 wherein the throw-off mechanism is also automatically responsive to the reestablishment of the vacuum to move the throw-01f lever back to last sheet out of the machinery into which it has dropped.

It is, therefore, a primary object of this invention to provide means whereby the feeding and delivery of further sheets may be automatically stopped upon failure of the sheet feeding means to properly feed a sheet or of the delivery means to deliver a sheet, without, .how-

ever, causing any sheet in process of feeding or delivery to be droppedinto the press mechanism.

., Another object is to provide such means which -may be rendered inoperative when desired, as

when starting printing or when printing curly or other difiicult sheets. -A further object is to provide such means whereby upon failure of the sucker tips to properly seize a sheet the sheet feeding means will vbe permitted to complete its cycle of feeding a sheet to the platen before being rendered inoperative.

Still another object of this invention is to provide such means wherein the suction may be cut ofi in both feed and delivery'means when desired so that the press need not be stopped upon cessation of feeding.

Other'objects of this invention will appear as the description proceeds.

To theaccomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is a front elevational view of a platen printing press incorporating the device of my invention;

Fig.2 is a top plan view of the valve control mechanism of my new device;

Fig. 3 is a front elevational view of nism of Fig. 2;

Fig. 4 is a side elevational view of such mechanism;

Fig.- 5 is a sectional view taken along the line 5-5 -on Fig. 2 through the air-blast control valve;

Fig.6 is a sectional viewtaken. along the.line -6--6 on Fig. 2 through the feeder line valve;

Fig. 7 is a sectional view taken along the.line on Fig. 2 through the safety mechanism andthrow-off valve;

Fig. 8 is a sectional view taken along the line 8-8 on Fig. 2 through the delivery line valve;

Fig. 9 is a vertical sectional view taken along the line 9-9 on Fig. 2 through the valve passages;

Fig. 10 is a vertical sectional view taken along the line' HJ,-lil on Fig. 2 through the valve cam shaft;

'Fig. 11 is a. sectional view through the feeder the mechavalvesimilar to Fig. 6 but showingsuch valve locked inopen position;

,Fig. 12 is a sectional view through the feeder valve similar to Fig. 11 but showing the safety locking mechanism;

Fig. '13,is a sectional view through the safety mechanism similar-to Fig. 7 but showing such mechanism in. operative position;

. Fig: 14 is asectional view through the delivery line valve similar to Fig. 8 but showing such valve locked in open position r .the casting (see Fig. 2).

Fig. 15 is a sectional view taken along the line |5|5 on Fig. 2 through the manual control valve;

Fig. 16 is a sectional view through such valve taken along the line Iii-l6 on Fig.

Fig. 17 is an elevational view of the valve member of the valve of Fig. 15;

Fig. 18 is an elevational View, partly in cross section, of the manual control means;

Fig. 19 is a top plan detail view of a portion of the control means taken along the line 19-19 on Fig. 6; and

Fig. 20 is a diagrammatic layout of the piping to show the interrelation of the operating parts.

Referring now more particularly to said drawings and especially Fig. 1 thereof, the device of my invention may be incorporated in a platen press comprising a main frame I having pivotally mounted thereon a bed (not shown) adapted to be oscillated by cam means driven by the main drive shaft 2 of the press, such shaft being provided with a fiy-wheel 3. Throw-off means is provided as described in Johnson Patent No. 2,185,440, for example, comprising means for oscillating the back shaft in its bearings so as to position the bed for printing and throw-off positions respectively, such means being well known in the art. Athrow-off lever 4 permits of manual operation, and means, including a plunger indicated at 5 operative upon failure of vacuum in the vacuum line to engage a bar 6 which is pivotally attached to the bed of the press and is reciprocated by oscillation thereof, acts to automatically move the lever into throw-off position. A feed table and sheet feeding means generally indicated at 8 are provided and delivery means 9 and delivery table It operate in cooperation therewith. The vacuum lines running to such throw-off mechanism, feeder, and delivery means respectively are indicated in dash lines where their depiction would otherwise confuse the drawings. Likewise the details of the supporting and operating mechanism for the feeder 8 are omitted since the precise means of operation of the same is no part of the present invention.

The device of my invention comprises an assemblage of valves and regulatory means therefor, such assemblage being generally indicated at H on Fig. 1 and illustrated in detail in certain of the other figures. More specifically such device comprises a casting l2 in which are formed passageways l3 and. M. Passage l3 communicates with tube l5 which leads to feeder vacuum line l6, and" passage |4 communicates with tube H which leads to delivery vacuum line |-8. Lines |9 and 20 come from the vacuum pump P (see Fig. 20) and supply suction to lines It and I8 respectively.

Casting I2 is secured to the frame I of the press by means of bolts 2| within spacer sleeves 22, such bolts passing through end portion 23 of A plate 24 is bolted to the other end of casting l2 and supports one end of shaft 25 on which arms 26, 21 and 28 are pivotally mounted, arms 26 and 28 being operative upon sufiicient oscillation to raise valve members 29 and as from their respective seats at the ends of passages i3 and I4, thus acting like tappet valves. A cam shaft 3| driven through bevel gear 32 passes beneath such arms and is operative upon rotation to rock the same through engagement of cams 33, 34, and 35 with cam rollers 36, 31 and 38 carried by arms 26, 21 and 28 respectively. The function ofarm 21 will be made clear below.

Depending from plate 24 is a cylinder 39 from the lower end of which line 40 communicates, such line carrying air under pressure from the pump for the air blast. From the side of such cylinder line 4| leads to valve 42 from which line 43 leads to the air blast means 44 (see Figs. 1, 3, and 20). A plunger 45 is reciprocable in cylinder 39 against theforce of coil spring 46 and when depressed is operative to'close line 4| where it leaves the cylinder (see Fig. 5). A cam 41 mounted on cam shaft 3| engages the upper end of such plunger and reciprocates the same in timed relationship to the raising and lowering of tappet valve members 29 and 30. Cam 41 is mounted in a manner to permit rendering it inoperative when it is not desired to have the air blast intermittently interrupted, being attached to a tube 48 which is slidable on the end portion of shaft 3| and locked for rotation therewith by means of pin 49 engaged in slot 50. in such shaft (see Fig. 10). By means of handle 5| cam 41 may then be moved to the right as viewed in Fig; 10 and into inoperative position, spring-backed ball 52 engaging either of two grooves in shaft 31 to hold the cam in the selected position.

Valve 42 comprises a cylinder 53 in which an inner cylindrical valve member 54 is rotatably and 'recipr oca'bly mounted. A coil spring 55 tends to raise such member which is keyed toa control rod 56 at its upper end and provided with a slot 51 in its lower'end' to permit passage of the air. Obviously, the higher member 54'is raised by spring 55 the more air will be permitted to pass. A handle 58 is secured to the upper end of rod 56 and is operative to rotate such rod and thereby such valve member. Rod 56 may be reciprocated in supporting bracket 59 by turning knurl-headed screw 60- which engages pivotally mounted lever arm 6| which in turn bears on collar 62 onsuch rod (Fig. 18). Thus by manipulation'of such screw the size of the valve passage afforded by slot 51 in member 54 may be adjusted, the valve member being forced down against spring 55 to provide a progressively smaller opening. One end of key pin 63 is adapted. toengage stops 64. and 651to. limit rotation of rod 56 and the valve member.

Line 66 leads from throw-off operating mechanism 5 above, described to passage 5.? in casting |2 (see Figs. 1, 4, '7, 13.and 20). A valve member 68 carried by finger 69' is adapted to. close the end of such passage. Finger 69 depends from plunger 19 reciprocably mounted in a cavity in casting l2 and is properlypositioned by means of guide member 1| sliding in hole 12; Plunger 10' is backed with a coil spring 13 tending to force such plunger outward and thus cause valvemenrber 68 to be unseated and the throw-off mechanism thrown into. operation. through the result.- ant failure of the. vacuum. in. line 65. Communie eating with the inner end of the cavity in which such cylinder snugly fits is a lateral passageway 14- cored in back plate 15. and connecting such cavity with passage, l4. It will be seen, there- .fore, that when the vacuum is. properly main tained: in the delivery lines and hence inv passage |i4 plunger 18 willbe held retracted against-1 the force of. the spring, but upon failure of the vacuum in the delivery lines plunger. Illw will move outward opening line 55 as above explained and causing the throw-off mechanism to operate.

Keyed to control rod 5.8 is an arm 16 connected 7 .by link 11* toarm i8, keyedtoshaft 1B journalled in. brackets and; 8|. Between such brackets an arm 82 is attached to shaft I9 the endportion.

of which is adapted to contact the end of plunger 19 and hold such plunger retracted against the force of spring 13 upon proper setting of handle 58 even when the delivery vacuum has failed.

1 Above plunger 18- a similarbut smaller plunger 63 protrudes from a cavity in casting l2 in which it fits snugly and is reciprocable. It likewise is backed by coil spring 84. tending to force it outwardly and the inner end ofthe cavity communicates by passage 85 with passage l3 which as above described is in connection with the feeder vacuum line. I

'Pivota1ly mounted on the face of casting I2 is a double-ended lever 86 the tail of which is engaged in a groove 8'! in'the end of plunger 83 '(Figs. 4, 8 and 13). -Thus when plunger 83 is retracted the head 88 of the lever will be held away from the ends of arms 21 and 28 but when such plunger has moved outward actuated by spring 84 upon failure of the vacuum in the feeder lines such head will be moved inwardly against the ends of arms 21 and 28 and as such arms are raised by cams 34 and 35 respectively such head will snap under the ends thereof preventing valve member 30 from again becoming seated. This, of course, has the effect of rendering the delivery suckers inoperative. Lip 89 on the end of arm 21 hooks over head 88 as shown in Fig. 13.

During normal operation of the press, however, when the feeder mechanism is functioning properly, when valve member 29 is unseated by action of cam 33, permitting plunger 83 to move outwardly, such outward action will be prevented by the tail of lever 86 engaging plunger 83 while the head 88 of such lever is held out in the position indicated in Fig. 8 by engagement with the end of arm 21 (see Fig. 4). By the time cam 34 has come around to raise arm 21 (which would then permit head 88 to move inwardly and block the seating of valve member 36) valve member 29 has again been seated, restoring the vacuum and causing plunger 83 to be held in thereby. Of

course, if there were continued failure-of the vacuum due to failure of the-sheet feeding mechanism to properly seize a sheet, plunger 83 would move outwardly and head 88 inwardly upon the raising of arm 21 to prevent seating'of member 30 and continued functioning of the delivery means. But it is clear that the delivery means will not be interrupted if in process of delivering a sheet until such sheet has been deposited on the delivery table.

Another double-ended lever 99' is pivotally mounted adjacent lever 86 and provided with a torsion spring 9| tending to force its head 92 outwardly and its tall 93 against the end of plunger 19. Upon failure of the vacuum in the delivery lines plunger will move outwardly under action 'of spring 13 causing head 92 of lever 90 to move inwardly against the ends of arms 26 and 21 and as such arms are raised by cams 33 and 34 "such head will snap thereunder and prevent valve 'member 29 from again becoming seated. This renders the feeder suckers inoperative and no -more sheets will be fed. Lip 89 on arm 21 and f'lip'94 on the end of arm 26 hook over head 92 as shown in Fig. 12. v v

However, during normal operation, when valve member 30 is unseated by action of cam 35 raisfing arm 28, plunger 10 although no longer held retracted by suction will nevertheless be Lmable .(see Figs. 6 and 19). 'on arm 26 is offset so that the upper end of lever have an opportunity to move inwardly to'prevent re-seating of valve member 29. Since valve member 39 will in the interim again have become seated, plunger 79 is now held in by the vacuum and head 92 will no longer be forced inward but on the contrary will beheld out by torsion spring 9|.

It is apparent that if, when valve member 39 becomes re-seated, there is nevertheless a failure of vacuum in the delivery lines due tofailure to properly seize a sheet, plunger 18 .will not be held retracted but will move outwardly causing head 92 of lever to move in under arm 26 as soon as arm 21 has been raised by cam 34. This obviously will prevent further functioning of the feeder suckers as above explained. It will also be noted, however, that should the delivery suckers fail to properly deliver a sheet the vacuum to the feeder suckers will not be interrupted until they have completed the feeding of another sheet (i..e. valve member 29 is only. prevented from being seated during the next cycle) and likewise the delivery means will deliver such last fed sheet since valve member 39 will not be prevented from normal seating until the failure of member 29 to become seated releases plunger 82 causing lever head 88 to move into position to prevent the lowering of arm 28.

As explained above and illustrated in Fig. 13, the throw-off will become operative upon failure of the vacuum in the delivery lines for any reason since outward movement of plunger 19 will unseat valve member 68.

Another double ended lever is provided beside lever 99 with a compression. spring 96' bearing against its lower end tending to force its upper end inward into position to-engage arm 26 (see Fig. 11) and prevent the seating of valve member 29 (thus suspending operation of the feeder and delivery suckers as above'explained) Usually (for normal operation) handle 58 and therefore arm 18 will be so set that cam 91 will bear against the lower end of lever 95 holding the upper end of such lever in inoperative position It will be noted that lip 94 95 cannot be caught thereby.

A consideration of the above description will indicate the manner in which the mechanism operates under different conditions. It is at once apparent that there are three general positions in which handle 58 may be set to obtain appropriate operation of the feeder and delivery means. In order to hold such handle in the selected position three grooves 96, 99 and H10 are pro- .vided in valve member 54 adapted to engage a spring-backed ball I 8| housed in the casing of valve 42.

When handle 58 is turned to rotate valve member 54 sufiiciently to close valve 42 there will, of

course, be no air passing to the'air blast means. Furthermore, arm 18 is turned by action of link 17' so that cam 91 no longer will bear against the lower end of lever 95 and the upper end of such lever will move in to engage arm 26 causing the delivery and feeder-suckers .to become inoperative. It is thus possibleto run the press with the feeder stopped and without having the delivery sucker pull the tympan off the platen. The press need not be stopped merely because feeding has ceased.' The throw-off is,of course, automatically operative throughout the time such conditions endure.

' The last described 7 I position is employed when starting up the press.

Handle 58 is then turned to open valve 42, starting. the air blast, and camming lever 95 into inoperative position". As above indicated, the head of lever 95 does not engage lip 94 of arm 26. Otherwise the mechanism would jam. Handle 58 is turned far enough to swing arm 82 (through action of arm I8, link H, arm 18 and shaft 19) into position shown in Fig. fiiwhere it is operative to hold plunger 10 retracted despite failure of vacuum in the feeder or delivery lines; As a result, it is possible to start the printing operation without having the suction automatically shut off due to failure of the delivery suckers to pick off a sheet during the first cycles of the press. Likewise, the throw-off is not operated upon failure of the delivery vacuum since arm 82 likewise acts to hold Valve member 68 seated. If the feeder vacuum should fail, however,'d-ue to failure to feed a sheet, the delivery will be rendered inoperative by plunger 83" moving out and the throw-off will also be made operative by reason of line I82 which connects line it to the throw-off. When the feeder next seizes a sheet the delivery will again be rendered operative and the throw-off inoperative so that generally printing will be interrupted for only one cycle. This setting of the device is not only useful when starting printing but may be retained when printing difiicult curly sheets and the like where an operator must be in attendance and .it is not desired that the feed and delivery be stopped automatically every time a sheet is missed. Link 11 has a toggle action in this position augmenting the ball Hil in groove 98 to lock handle 58 since otherwise spring 13 might force lever 82 outwards.

If the operator wishes to set the device for safety position he will now turn handle 58 back to an intermediate position (ball llll engaging groove 99) with cam 91 still holding lever 95 in inoperative position. As above described, if the delivery now fails to deliver a sheet the resultant failure of vacuum will permit plunger I0 to move outwardly as soon as arm 21 is raised by cam 34 and head. 82 of. lever 90 moves beneath arm 26. feeder is thereby prevented since valve member 29 cannot again become seated (but not until the sheet in course of feeding has been placed on the platen) and the vacuum now also fails in the feeder line. This in turn permits plunger .83 to move out and likewise prevents re-seating of valve member 30 so that after the last fed sheet is delivered the delivery means becomes inoperative. Lip 94 on the end of arm 26- and lip 89 on the end of arm 21 prevent the escape of head 92 of lever 98 when plunger 10 is again retracted during the delivery of such last fed sheet. Otherwise the feeder would be enabled to feed yet another sheet. The throw-off is automatically operated as soon as plunger 18 moves out without the time lag which would occur if sole reliance were placed. onv the unseating of valve member 29 and consequent failure of vacuum in line I82. Passage 51 in valve member 54 is sufiiciently wide that passage of air to the air-blast. is permitted in both of the last two positions above described.

Similarly, when the feeder has failed to seize a sheet, plunger 83. moves out to render the delivery means inoperative and lip 89 prevents .the upper end 88 of lever 86' from escaping from beneath arm 28 after it. has once assumed such position.

To start the feed and delivery means again handle 58 is turned to the second position above Further action ofthe.

described witharm 82 holding plunger 10 retracted, later turning to the safety setting when the machine is operating properly. Even should the handle then be turned to the first described position permitting lever 85' to engage arm 26, one cycle of feed and delivery would be completed before valve members 29 and 30 are locked inopen position.

It will be seen from the foregoing that the objects of this invention have been achieved and a suction control device provided of great flexibility in operation. All possibility of damage to either the press or form is avoided even in the absence of the operator through automatic operation of such device so that one operator may satisfactorily tend a number of presses.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed. "I therefore particularly point out and distinctly claim as my invention:

1. In a platen printing press, feed means for feeding sheets to the platen, delivery means for delivering sheets from the platen, means automatically operative upon failure of said delivery means to properly engage a sheet on the platen to render said feed and delivery means inoperative, and delay means associated therewith operative to cause said feed means to complete the feeding of the next sheet in succession to the platen before becoming inoperative.

2. In a platen printing press, feed means for feeding sheets to the platen, delivery means for delivering sheets from the platen, means automatically operative upon failure of said delivery means to properly engage a sheet to render said feed and delivery means inoperative, and means operative to delay the action of said automatic means until after completion of one cycle of such press. I

3. In a platen printing press, suction feed means for feeding sheets to the platen, suction delivery means for delivering sheets from the platen, means automatically operative upon failure of said delivery means to properly remove a sheet from the platen to render saidfeed and delivery means inoperative by withholding the suction therefrom, and delay means preventing operation of said automatic means to withhold suction from said feed means until said feeding sheets to the platen, delivery means for delivering sheets from the platen, throw-off means operative to withhold the platen from impression relationship with the form ofsuch press, means automatically operative upon failure of said delivery means to properly remove a sheet from the platen to actuate said throwoif means and render said feed and delivery means inoperative, and delay means causing said feed means to complete the feeding of the next sheet in succession to the platen before becoming inoperative.

5-. In aplaten printing press, feed means for feeding sheets to the platen, delivery means: for delivering sheets from the platen, throw off means operative to withhold the platen. from impression relationship with the form of such press, safety means automatically operative upon failure of said delivery meansto properly remove a'sheet from the platen to render saidfeedand delivery means'inoperative, delay means associated with saidsafety'means causing said feed means to complete the feeding of the next sheet in succession to the platen before becoming inoperative, and meansfor making said safety means inoperative."

' 6. In a platen printing press, feed means for feeding sheets to the platen, delivery means for delivering sheets from 1 the platen, throw-off means operative upon failure of the delivery means to remove a sheet from the platen to withhold the platen from impression "relationship with the form of such press, safety means automatically operative upon failure of said delivery means to remove a sheet from the platen to render said feed and delivery means inopera+ tive, delay means associated with said safety means causing said feed means to complete the feeding of the next sheet 'in succession to the platen before becominginoperative, means' for making I said safety means inoperative, and manual 'means for making said feed and *delivery means inoperative." Y r r 7. In a platen printing press, feed means for feeding sheets to the platen, delivery means for delivering sheets from the platen, means automatically operative upon failure ofsaid delivery means to properly remove a sheet from the platen to render said feed and delivery means inoper ative, and delay means associated therewith causing saidfeed means first to complete the feeding of the next sheet to the platen and the delivery means to remove such sheet from: the platen before becoming inoperative.

8. In a platen printing press, suction means for feedingsheets to a platen, other suction means for delivering such sheets from such platen, vacuum lines leading to said respective suction means, valves in said lines communicating with theatmosphere, means operative to open andclose said valves in timed relationship, and means operative, upon failure of vacuum in one of said lines due to failure of a said suction means to pick up a sheet, to prevent closing of the said valve in the other of said lines when said valve is next opened. a I

9.'In' 'a platen printing press,'suction means for feedingsheets to a platen, other suction means for delivering such sheets from such platen, vacuum lines leading to said; respective suction means, valves in'said lines communicating with the atmosphere, means operative to open and close said valves in timed relationship; means operative, upon failure of vacuum in one of said lines due to failure of a said suction means to pick up a sheet, to prevent closing ofthe said valve in the other of said lines when said valve is next opened, and means operative; upon the consequent failure of vacuum in said last-named line, to prevent the closing of the said valve in said first-named line when said valve is next opened.

10. In a platen printing press, suction means for feeding sheets to a platen, other suction means for delivering such sheets from such platen, a vacuum line leading said feeder suction means, another vacuum line leading to said delivery suction means, a valve in said feeder vacuum line communicating with the atmosphere, a. valve in said delivery vacuum line communieating with the atmosphere, means operative to open and close said valves in timed relationship, means operative, upon failure of vacuum in said delivery vacuum line due to failure of said delivery suction means to pick up a sheet, to prevent closing of said valve in said feeder vacuum line when said valve is next opened, and means operative, upon consequent failure of vacuum in said feeder line, to prevent the closing of the said valve in said delivery vacuum line when said last-named valve is next opened.

11. In a platen printing press, suction means for feeding sheets to a platen, other suction means for delivering such sheets from. such platen, a vacuum line leading to said feeder suction means, another vacuum line leading to said delivery suction means, a valve in said feeder vacuum line communicating with the atmosphere, a valve in said delivery vacuum line communicating with the atmosphere, means operative to open and close said valves in timed relationship, means operative, upon failure of vacuum in said delivery vacuum line due to failure of said delivery suction means to pick up a sheet, to prevent closing of said valve in said feeder vacuum line when said valve. is next opened and to throw. the throw-off means of the press into operation, and means operative, upon consequentfailure-of vacuum in said feeder line, to prevent the closing of the said valve in said delivery vacuum line when said last-namedvalve is next opened.

12. In a platen printing press, suction means for feeding sheets to a platen, other suction means for delivering such sheets from such platen, a vacuum line leading to said feeder suction means, another vacuum line leading to said delivery suction means, a valve in said feeder vacuum line communicating with the atmosphere, a valve in said delivery vacuum line communicating with the atmosphere, means operative to open' and close said valves in timed relationship, a'spring-backed plunger adapted to be held re-' tracted by the vacuum in said delivery vacuum line when said delivery suction means is delivering a sheet and by mechanical means when said valve in said delivery vacuum line is open, a second spring-backed plunger adapted to be held retracted by the vacuum in said feeder vacuum line when said feeder suction means is feeding a sheet and by mechanical means when said valve in said feeder vacuum line is open, said plungers being operativeto move outward-1y upon failure of vacuum due to failure of said delivery suction means and said feeder suction means respectively to seize a sheet, means actuated by outward movement of said first-named plunger to prevent closing of said valve in said feeder vacuum line when said valve is next opened, and means actuated by outward movement of said second plunger to prevent closingof said valve in said delivery vacuum line when the latter said valve is next opened.

13, In a platen printing press, suction means for feeding sheets to a platen, other suction means for delivering such sheets from such platen, a vacuum line leading to said feed suction means, another vacuum line leading to' said delivery suction means, a valve in said feeder vacuum line communicating with the atmosphere, a valve in said delivery vacuum line communicating with the atmosphere, means operative to open and close said valves in timed relationship, a spring-backed plunger adaptedto be held re tracted by the vacuum in said delivery vacuum line when said delivery suction means is delivering a sheet and by mechanical means when said valve in said delivery vacuum line is open, a second spring-backed plunger adapted to be held retracted by the vacuum in said feeder vacuum line when said feeder suction means is feeding a sheet and by mechanical means when said valve in said feeder vacuum line is open, said plungers being operative to move outwardly upon failure of vacuum due to failure of said delivery suction means and said feeder suction means respectively to seize a sheet, means actuated by outward movement of said first-named plunger to prevent closing of said valve in said feeder vacuum line when said valve is next opened, means actuated by outward movement of said second plunger to prevent closing of said valve in said delivery vacuum line when the latter said valve is next opened, and other means actuated by outward movement of said first-named plunger operative to throw the throw-off means of such press into operation.

14. In a platen printing press, suction means for feeding sheets to a platen, other suction means for delivering such sheets from such platen, a vacuum line leading to said feeder suction means, another vacuum line leading to said delivery suction means, a tappet valve in said feeder vacuum line communicating with the atmosphere, a tappet valve in said delivery vacuum line communicating with the atmosphere, cam means operative to open and close said valves in timed relationship, a spring-backed plunger adapted to be held retracted by the vacuum in said delivery vacuum line when said delivery suction means is delivering a sheet and by mechanical means when said valve in said delivery vacuum line is open, a second spring-backed plunger adapted to be held retracted by the vacuum in said feeder vacuum line and by mechanical means when said valve in said feeder vacuum line is open, said plungers being operative to move outwardly upon failure of vacuum due to failure of said delivery suction means and said feeder suction means respectively to seize a sheet, lever means actuated by outward movement of said first-named plunger to prevent closing of said tappet valve in said feeder vacuum line when said valve is next opened, and lever means actuated by outward movement of said second plunger to prevent closing of said valve in said delivery vacuum line when the latter said valve is next opened.

15. In a platen printing press, suction means for feeding sheets to a platen, other suction means for delivering such sheets from such platen, a vacuum line leading to said feeder suction means,-another vacuum line leading to said delivery suction means, a tappet valve in said feeder vacuum line communicating with the atmosphere, a tappet valve in said delivery vacuum line communicating with the atmosphere, cam means operative to open and close said valves in timed relationship, a spring-backed adapted to be held retracted by the vacuum in said delivery vacuum line when said delivery suc tion means is delivering a sheet and by mechan-' ical means when said valve in said delivery vacuum line is open, a second spring-backed plunger adapted to be held retracted by the vacuum in said feeder vacuum line and by mechanical means when said valve in said feeder vacuum line is open, said plungers being operative to move outwardly upon failure of vacuum due to plunger failure of said delivery suction means and said feeder suction means respectively to seize a sheet, lever means actuated by outward movement of said first-named plunger to prevent closing of said tappet valve insaid feeder vacuum line when said valve is next opened, lever means actuated by outward movement of said second plunger to prevent closing of said valve in said delivery vacuum line when the latter said valve is next opened, and manually controlled means operative to prevent outward movement of the said firstnamed plunger when it is not desired that the vacuum to the said feeder suction means beinterrupted when the said delivery suction means fails to seize a sheet. 16. In a platen printing'press, suction means for feeding sheets to a' platen, other suction means for delivering such sheets from such platen, a vacuum line leading to said feeder suction means, another-vacuum line leading to'said delivery suction means, a tappet valve in said feeder vacuum line communicating with the atmosphere, a tappet valve in said delivery vacuum line communicating with the atmosphere, cam means operative to open and close said valves in timed relationship, a spring-backed plunger adapted to be held retracted by the vacuum in said delivery vacuum line when said delivery suction means is delivering a sheet and by mechanical means when said valve in said delivery vacuum line is open, a second spring-backed plunger adapted to be held retractedby the vacuum in said feeder vacuum line and by mechanical means when said valve in said feeder vacuum line is open, said'plungers being operative to move outwardly upon failure of vacuumdueto failure of said delivery'suction means and said feeder suction means respectively to seize a sheet, lever means actuated by outward movement of said first-named plunger to prevent closing of said tappet valve in said feeder vacuum line when said valve is next opened, lever means actuated by outward movement of said second plunger to prevent closing of said valve in said delivery vacuum line when the latter said valve is next opened, manually controlled means operative to prevent outward movement of the said firstnamed plunger when it is not desired that the vacuum to the said feeder suction means be interrupted when the said delivery suction means fails to seize a sheet, and manually controlled means operative to prevent said valve in said feeder vacuum line from closing when it is desired to run the press without feeding or delivering sheets.

1'7. In a platen printing press, feed means for feeding sheets to the platen, delivery means for delivering sheets from the platen, means automatically operative upon failure of said delivery means to remove a sheet from the platen to render said feed and delivery means inoperative, delay means rendering said automatic means temporarily inoperative until after said feed means has first completed the feeding of the next sheet to the platen and the delivery means has removed such sheet from the platen, and means for rendering said automatic means inoperative when desired.

WILLIAM C. RUPP. 

